patch 9.1.0559: translation of vim scripts can be improved

Problem:  translation of vim scripts can be improved
          (after v9.1.0509)
Solution: improve documentation, add tests, include missing
          libraries for the Windows CI
          (RestorerZ)

closes: #15100

Signed-off-by: RestorerZ <restorer@mail2k.ru>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/test_gettext_makefile_in4.vim b/src/testdir/test_gettext_makefile_in4.vim
new file mode 100644
index 0000000..7f9f3f7
--- /dev/null
+++ b/src/testdir/test_gettext_makefile_in4.vim
@@ -0,0 +1,6 @@
+" Test file for gettext() package makefile
+" Last Change:	2024 Jun 01
+
+echo gettext("This is a test", "test_gettext")
+echo gettext("This is a fourth test", "test_gettext")
+" vim: ts=8